Incidence, Virulence Factors, and Clonality among Clinical Strains of Non-O1, Non-O139 Vibrio cholerae Isolates from Hospitalized Diarrheal Patients in Kolkata, India

摘要: The incidence of Vibrio cholerae non-O1, non-O139 strains from hospitalized patients with acute diarrhea constituted 27.4% (n = 54) the total 197 V. isolated in Kolkata, India, 2003. Of strains, 135 were identified as O1 serotype Ogawa and 2 O139. In same time period, six background rough that possessed all known virulence factors identified. Serotype analysis placed 42 into 19 serogroups, while 12 remained O nontypeable (ONT); existing serotyping scheme involved antisera to 206 serogroups. Detection a good number ONT suggested additional serogroups have arisen need be added current scheme. nontoxigenic except for an O36 strain (SC124), which regulated expression cholera toxin classical did. Additionally, SC124 carried alleles tcpA toxT different those counterpart, these also found five clonally related belonging Strains carrying exhibited higher colonization animal model compared lacking tcpA. PCR-based analyses revealed remarkable variations distribution other factors, including hlyA, rtxA, seventh pandemic island I (VSP-I), VSP-II, type III secretion system (TTSS). Most contained hlyA (87%) rtxA (81.5%) secreted cytotoxic when grown vitro. Approximately one-third (31.5%) TTSS gene cluster, most more motile hemolytic against rabbit erythrocytes. Partial nucleotide sequence TTSS-containing silent mutations within vcsN2 (type cytoplasmic ATPase), indicating functional conservation apparatus.